Not until ___to do my homework ____ how much time I had wasted playing computer games.

A．I began; I realized

B．I began; did I realize

C．did I begin; I realized

D．did I begin; did I realize

地方政府之间纵向关系的基础是政府间的（）关系。

A.平行

B.交叉

C.指导

D.管辖